| Title: |
CO 2 -plant effects do not account for the gap between dryness indices and projected dryness impacts in CMIP6 or CMIP5 |
| Authors: |
Scheff, Jacob; S Mankin, Justin; Coats, Sloan; Liu, Haibo |
| Contributors: |
Climate Program Office; University of North Carolina at Charlotte; Dartmouth College |
| Source: |
Environmental Research Letters ; volume 16, issue 3, page 034018 ; ISSN 1748-9326 |
| Publisher Information: |
IOP Publishing |
| Publication Year: |
2021 |
| Description: |
Recent studies have found that terrestrial dryness indices like the Palmer Drought Severity Index (PDSI), Standardized Precipitation Evapotranspiration Index (SPEI), and Aridity Index calculated from future climate model projections are mostly negative, implying a drying land surface with warming. Yet, the same models’ future runoff and bulk soil moisture projections instead show regional signals of varying sign, and their vegetation projections show widespread greening, suggesting that the dryness indices could overstate climate change’s direct impacts. Most modeling studies have attributed this gap to the indices’ omission of CO 2 -driven stomatal closure. However, here we show that the index-impact gap is still wide even in future-like model experiments that switch off CO 2 effects on plants. In these simulations, mean PDSI, Aridity Index, and SPEI still decline broadly with strong warming, while mean runoff, bulk soil moisture, and vegetation still respond more equivocally. This implies that CO 2 -plant effects are not the dominant or sole reason for the simulated index-impact gap. We discuss several alternative mechanisms that may explain it. |
| Document Type: |
article in journal/newspaper |
| Language: |
unknown |
| DOI: |
10.1088/1748-9326/abd8fd |
| DOI: |
10.1088/1748-9326/abd8fd/pdf |
| Availability: |
https://doi.org/10.1088/1748-9326/abd8fd; https://iopscience.iop.org/article/10.1088/1748-9326/abd8fd; https://iopscience.iop.org/article/10.1088/1748-9326/abd8fd/pdf |
| Rights: |
http://creativecommons.org/licenses/by/4.0 ; https://iopscience.iop.org/info/page/text-and-data-mining |
| Accession Number: |
edsbas.F85D6D19 |
| Database: |
BASE |